The present description, drawings and claims relate to a computer input device, and more particularly to a computer input device such as a computer mouse with a scroll function. Nowadays, using a computer mouse with a scroll device (e.g., a scroll wheel or a scroll pad) provides a simple means for navigating up, down, to the left or the right in a content, folder or document presented on a computer screen. Generally, a conventional mouse communicates with a host computer via a USB cable or a wireless interface, such as Bluetooth®. The so-called “scrolling” function in applications is mentioned in U.S. Pat. No. 5,530,455, referring to a roller-like device included at the top of a computer mouse. Once the roller is rotated by a user's finger, the non-displayed portion of an application or document can be displayed line-by-line or page-by-page. A rapid turning of the roller generates pulses which are stored in a buffer and interpreted as a scroll command so that scrolling continues until stopped or until the buffer is depleted.
When using a conventional mouse with a scroll wheel, one-step turning of the scroll wheel may result in one-line or several-line scrolling of screen content on a computer display, depending on the computer system and the system configuration. Thus, when a user needs to scroll through a long document or to do a fast browsing, the scroll wheel has to be turned numerous times. This is inconvenient for the user. Allowing both precise repositioning actions as well as rapid movement across large distances are conflicting requirements. Scrolling has a wide range of control requirements: from small precise pixel targeting to long range movement. Many scrolling input devices, however, allow only coarse levels of control. The range of physical movement enabled by most mouse scroll wheels is approximately 10 mm linearly (without temporarily disengaging from the wheel in order to reposition the finger). In addition, this movement is discretized into a small number of coarse ‘notches’. Documents can be hundreds of pages long, with each page containing roughly a thousand linear pixels, any of which could be a target for positioning the scrolled display. Therefore, standard notched scroll wheels are best used only for short range movement, and when longer movements are required users switch to an alternative control, such as dragging a scroll thumb of a vertical or horizontal scroll bar. Such a distance-based choice between scrolling methods is inefficient as it takes time, can be incorrect, and requires the user to switch their attention from the task to the interface. Thus, users may avoid the decision and use the scroll wheel for long distances, even when this takes far longer than using the thumb of the scroll bar. Since scroll wheels are wide-spread, it is reasonable to expect that these controls should be usable for reaching near targets as efficiently as far targets. Conventional scrolling devices report raw events corresponding to the degree of a user's manipulation, which is translated into a magnitude of movement (measured in number of lines or pixels) by software device drivers execute in the host computer. The software device drivers can also attend to the reported value and the time since the last event and use these to apply transformations to the device events.
Andy Cockburn et al, in “Improving Scrolling Devices with Document-Length-Dependent Gain”, CHI 2012, May 5-10, 2012, Austin, Tex., USA. ACM 978-1-4503-1015-Apr. 12, 2005, discloses that document-length dependent gain can improve performance with scrolling devices. However, this approach requires data exchange of the document length from the high level program (text processor, web browser, spreadsheet program, operating system, or the like) and the mouse software device driver executed in the host computer.
Logitech's MicroGear Precision Scroll Wheel (see “Innovation Brief: Logitech MicroGear™ Precision Scroll Wheel and SmartShift™ Technology” (source: http://www.logitech.com/lang/pdf/ib-microgear_and_smartshift_EN.pdf) is a mechanical concept for navigating documents etc. that operates in two distinct modes. In a free-spin mode, a ratchet-scrolling mechanism retracts, allowing the wheel to spin for several seconds to provide frictionless long-distance scrolling. In its normal click-to-click mode, the wheel allows to navigate small distances with great precision, such as individual spreadsheet rows, or small vertical distances in a document or Web page. Switching between the two modes is either done manually or managed automatically. To free-spin, a 14-gram metal wheel cooperates with a ratcheting hub. To shifting into fast mode requires nearly a hundred mechanical components, including a low-power motor to retract the ratcheting mechanism for free-spinning. When a text document is the user's focus, the wheel defaults to free-spin mode, but is set to click-to-click mode by the software driver when the user is navigating photos in a photos folder. For spreadsheets, the software driver also senses the speed at which the wheel is spun. If it is spun fast, the wheel is put into free-spin mode; if the wheel is spun more slowly, the software driver causes the wheel to shift into click-to-click mode. With the ratchet mechanism disengaged, the scroll wheel can spin freely, allowing to scroll great distances fast. As the wheel comes to a stop, the cam rotates in the opposite direction, reengaging the ratchet mechanism and returning the mouse to normal operation.
U.S. Pat. No. 8,587,521 B2 refers to a computer mouse that notifies a mouse driver in the host computer whenever a scroll event occurs as a result of rotation of a scroll wheel. In response to receiving a notification of a scroll event, the mouse driver adjusts a stored value that represents inertia calculated based on elapsed time between scroll events. The computer scrolls a number of lines on a display, the number being based on the stored value. When the stored value does not represent zero inertia and upon a predetermined amount of time elapsing without occurrence of a scroll event, the computer scrolls a second number of lines on the display. The second number is based on the stored value. The mouse driver adjusts the stored value so as to represent a decrease in inertia.
US 20070200826 A1 refers to an input device that includes a body and a trace-detecting module coupled to the body. The body has a micro control unit (MCU), and the trace-detecting module has a light pervious area, and a trace-detecting unit. The trace-detecting unit has a light source and a sensor. The sensor senses changes in a reflected light beam caused by movement of a user's digit on the light pervious area at a velocity which can be sensed by the sensor. If the velocity exceeds a threshold stored in the MCU, the MCU executes automatic scrolling at a predetermined scrolling speed.
US20070146324 refers to further prior art useful as background for understanding the concept presented herein.